Faulty Rudder Control, Pilots’ Response Led to AirAsia Crash

Faulty equipment and the pilots’ response to the malfunctions contributed to the crash of an Indonesian AirAsia jet past year, investigators said on Tuesday (Dec 1).

No distress signal was issued, and investigators said weather conditions did not play a role in the crash.

In their report, Indonesia’s National Transportation Safety Committee revealed the sequence of events which led to flight QZ8501 disappearing from the radar.

The Guardian reports that that the Airbus A320-200 was en route to Singapore from the Indonesian city of Surabaya on 28 December when it lost contact with air traffic control around 42 minutes after takeoff.

Indonesia’s National Transport Safety Committee reported maintenance records for the airbus show the system experienced 23 malfunctions previous year, with shorter and shorter intervals between incidents within three months before the deadly crash.

The report says the plane had banked sharply at one point, and the crew struggled to bring it back under control. The crew could not recover control of the craft after it entered a “prolonged stall condition”.

Marjono Siswosuwarno, head of the investigators at KNKT, said there were no indications that the weather had affected the aircraft.

Family members of those killed in the accident had been waiting anxiously for the report, and Eka Santoso – whose brother, sister-in-law and their two children died in the crash – urged AirAsia to take action following its recommendations. “To make the plane go down you need to push, so this order was confusing”, said accident investigator Nurcahyo Utomo. The problem was initiated by a crack in the soldering on the circuit board of the rudder travel limiter unit (RTLU).

The crew tried to fix the problem by resetting the computer system, but this disabled the autopilot.

“It should be a big question for the airline”, she said, adding that if the plane had been properly maintained, the problem would have been flagged and repaired.

The plane reached an altitude of 38,000 feet before falling at a maximum speed of 20,000 feet per minute. Only 106 bodies have been retrieved so far.

Fernandes stressed that aviation authorities would “not leave any stone unturned” in ensuring that lessons would be learned from the tragedy.